The cat that lives in my backyard is his own man. He comes and goes as he pleases. He politely asks for food but when it doesn’t meet his expectation, he complains to the chef. He doesn’t like to be tied down but he’s not above showing his affection when his belly is full and it’s raining outside. He tolerates petting as a courtesy to those who serve him but his eyes belie his disdain for the cooing and snuggling that are sometimes inflicted upon him by his co-tenants.

Chicago Street Art

His is a pretty sweet life. Recently, I’ve found myself envying his advanced Buddhist practice of living purely in the moment. He does not plan for the future or regret past decisions. He is focussed entirely on the present and his behavior reflects only his most immediate needs. But he does have one major character flaw: when a choice is forced upon him, even if it is a desirable alternative or would have been his preferred action in any case, he cannot tolerate it. For example, it has become his habit, after dinner, to enjoy stretching out on a warm blanket near his chef. But if his exit from the room is blocked by a closed door, he will not settle down for a snooze, but will do everything he can to get out of the room. Once the door is opened, he ignores it and proceeds to sidle up to the chef with his motor in full purr mode.

On one level, I understand his angst: when I am told that I must do something, that action loses a part of its attraction. And I don’t like to feel boxed in or powerless to escape if circumstances change. But, after five years of having my needs met, and never once being hurt or trapped, I have learned to trust the person (and cat) with whom I share my living space. Part of this trust comes from my ability to predict the actions of my co-tenants based on thousands of observations over the years. These observations have been stored, some as vivid episodes, others as extractions of the regularities in my co-tenants’ behaviors, in my malleable brain.

Memory for episodes, in particular, fascinates me for two reasons: the first being that our autobiography, and to a large extent our identity, is made up of our memories of the past, and feels to us like a searchable database of our experience (more here) and the second being the extraordinary observation that patients who lose the ability to retain event memories are also unable to imagine the future (the case of K.C.described here). I’ve studied autobiographical memory for over a decade, from my very first published paper (found here) to the one that’s currently in the STUFF TO DO NOW folder on my desktop.

As neuroscientists have come to navigate the ever-shifting landscape of our personal memories, it has become increasingly clear that our representations of the past and the future overlap to a very large extent. A former lab-mate of mine, who finished her PhD with the supervisors of my very first project (Dr. Morris Moscovitch and Dr. MaryPat McAndrews, at the University of Toronto, co-authors on my first published paper), went on to complete a highly-successful post-doctoral fellowship at Harvard with (another U of T alum) Dr. Daniel Schacter. Donna Addis is a sweet, intelligent and dynamic woman (now a professor in her own right at the University of Auckland) who conducted a seminal neuroimaging study demonstrating that the brain regions that support episodic memory (the medial temporal lobe, the core of which is the hippocampus, as well as areas of dorsolateral prefrontal and parietal cortices) are also involved in imagining the future (paper available here).

Most married couples, among other people, know that memory is a constructive process, rather than an accurate recording of what actually happened. For a long time, this constructive aspect of event memory was seen as a short-coming, rather than a desirable feature. But Dan Schacter and Donna Addis suggested that we should rethink this negative connotation and think about the benefits of a constructive memory system. Specifically, they suggested that this feature enables us to pull together bits of our past, recombine them and imagine the consequences of our actions in the future. Our constructive memory system gives us the tools we need to become effective soothsayers.

This ability gives me an edge over Mr. Cat in many different ways. I can dream big, and imagine every step that I need to take in order to make that dream come true. I can delay immediate gratification for a bigger reward down the line. I can adapt to changing circumstances because I can alter my imagined future to account for new information. But this ability can also draw me out of the present and prevent me from enjoying the moment because I’m too busy planning for the future. I’ve got a lot of decisions to make in the coming weeks and I need Mr. Cat to remind me that when the door is open, my belly is full and it’s raining outside, it’s perfectly ok to snooze with the chef.

Tags: mental time travel, predicting the future, cats, dorsolateral prefrontal cortex, hippocampus, medial temporal lobe, fmri